An infrared thermometer is a device for measuring body or surface temperature without direct contact. The main device in the thermometer mechanism is the pyrometer. The pyrometer reacts to the intensity of infrared (thermal) radiation from the body. By determining the amount of infrared energy emitted by an object and its emissivity, an infrared thermometer determines the range of the actual body temperature. Infrared thermometers are a subset of devices known as "thermal radiation thermometers". Infrared thermometers are widely used in medicine, industrial industry and construction.